Answered by Shaykh Yūsuf Badāt
A woman’s menstruation ends whilst she is on a flight. What would be the advice? Can she do tayammum and perform ṣalāt. What about if she was at the airport?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allāh, Most Gracious, Most Merciful.
Jazāk Allāh Khayr/ Thank you for contacting Mathābah Institute.
Regardless where the menses end, in order for prayers etc. to be performed, one must make ghusl. In a flight, it is almost impossible to perform ghusl, therefore if tayammum was done, the prayer will be required to be repeated once ghusl is performed. However, one will not be sinful in such dire situation for delating the prayer after its fixed timing. In an airport, usually there are shower facilities. If one has sufficient time before boarding a flight, they should use the shower facility and pray. Otherwise, again if tayammum is adopted, the prayer will be repeated once ghusl is performed. Also, worthy to note is that during travel one can join two prayers. In this manner, it becomes easier to adjust ṣalāh after one has completed their menses in travel. – (See: Al-Fatāwā Al-Hindīyyah, Vol 1, Page 28, Dār Al-Fikr)
Only Allāh knows best
 فَإِنْ وَجَدَ خَادِمًا أَوْ مَا يَسْتَأْجِرُ بِهِ أَجِيرًا أَوْ عِنْدَهُ مَنْ لَوْ اسْتَعَانَ بِهِ أَعَانَهُ فَعَلَى ظَاهِرِ الْمَذْهَبِ أَنَّهُ لَا يَتَيَمَّمُ لِأَنَّهُ قَادِرٌ كَذَا فِي فَتْحِ الْقَدِيرِ – كتاب الفتاوى الهندية ج ١/ ص ٢٨ دار الفكر